The prior art discloses a variety of monitoring devices for use with a dishwasher cycle. A first example of the smart rack and machine system of Thomas U.S. Pat. No. 6,463,940, in which each type of article is detected and washed according to its own pre-determined condition.
Batcher, U.S. Pat. No. 7,437,213, teaches a method and system for monitoring performance of a warewasher and which includes RFID tags placed into individual washer racks. The tags are in communication with a host computer for monitoring performance.
Other references of note include the dishwasher with imaging device of Ashrafzadeh U.S. Pat. No. 8,696,827, along with the dishwashing machine of Rolek U.S. Pat. No. 8,529,705 which includes a dispenser configured to receive a dishwashing tablet and a sensor operable to identify the dishwashing tablet, with an electronic controller selecting a dishwasher cycle based on the identify of the dishwashing tablet.
Humphner, U.S. Pat. No. 2,223,106, teaches a tax label with a paper base printed thereon in water insoluble ink indicating cancellation, with a water soluble adhesive and light impermeable pigmented layer extending over and concealing the printing, and over which a final print is provided on the pigmented layer.